OpenRaiser/Intern-Atlas huggingface dataset:
On rho in a Decision-Theoretic Apparatus of Dempster-Shafer Theory
Venue: arXiv cs.AI 2003
Year: 2003

Thomas M. Strat has developed a decision-theoretic apparatus for Dempster-Shafer theory (Decision analysis using belief functions, Intern. J. Approx. Reason. 4(5/6), 391-417, 1990). In this apparatus, expected utility intervals are constructed for different choices. The choice with the highest expected utility is preferable to others. However, to find the preferred choice when the expected utility interval of one choice is included in that of another, it is necessary to interpolate a discerning point in the intervals. This is done by the parameter rho, defined as the probability that the ambiguity about the utility of every nonsingleton focal element will turn out as favorable as possible. If there are several different decision makers, we might sometimes be more interested in having the highest expected utility among the decision makers rather than only trying to maximize our own expected utility regardless of choices made by other decision makers. The preference of each choice is then determined by the probability of yielding the highest expected utility. This probability is equal to the maximal interval length of rho under which an alternative is preferred. We must here take into account not only the choices already made by other decision makers but also the rational choices we can assume to be made by later decision makers. In Strats apparatus, an assumption, unwarranted by the evidence at hand, has to be made about the value of rho. We demonstrate that no such assumption is necessary. It is sufficient to assume a uniform probability distribution for rho to be able to discern the most preferable choice. We discuss when this approach is justifiable.
Specifying nonspecific evidence
Venue: arXiv cs.AI 2003
Year: 2003

In an earlier article [J. Schubert, On nonspecific evidence, Int. J. Intell. Syst. 8(6), 711-725 (1993)] we established within Dempster-Shafer theory a criterion function called the metaconflict function. With this criterion we can partition into subsets a set of several pieces of evidence with propositions that are weakly specified in the sense that it may be uncertain to which event a proposition is referring. Each subset in the partitioning is representing a separate event. The metaconflict function was derived as the plausibility that the partitioning is correct when viewing the conflict in Dempster's rule within each subset as a newly constructed piece of metalevel evidence with a proposition giving support against the entire partitioning. In this article we extend the results of the previous article. We will not only find the most plausible subset for each piece of evidence as was done in the earlier article. In addition we will specify each piece of nonspecific evidence, in the sense that we find to which events the proposition might be referring, by finding the plausibility for every subset that this piece of evidence belong to the subset. In doing this we will automatically receive indication that some evidence might be false. We will then develop a new methodology to exploit these newly specified pieces of evidence in a subsequent reasoning process. This will include methods to discount evidence based on their degree of falsity and on their degree of credibility due to a partial specification of affiliation, as well as a refined method to infer the event of each subset.
Robust Report Level Cluster-to-Track Fusion
Venue: arXiv cs.AI 2003
Year: 2003

In this paper we develop a method for report level tracking based on Dempster-Shafer clustering using Potts spin neural networks where clusters of incoming reports are gradually fused into existing tracks, one cluster for each track. Incoming reports are put into a cluster and continuous reclustering of older reports is made in order to obtain maximum association fit within the cluster and towards the track. Over time, the oldest reports of the cluster leave the cluster for the fixed track at the same rate as new incoming reports are put into it. Fusing reports to existing tracks in this fashion allows us to take account of both existing tracks and the probable future of each track, as represented by younger reports within the corresponding cluster. This gives us a robust report-to-track association. Compared to clustering of all available reports this approach is computationally faster and has a better report-to-track association than simple step-by-step association.
The Evolution of the Computerized Database
Venue: arXiv cs.DB 2003
Year: 2003

Databases, collections of related data, are as old as the written word. A database can be anything from a homemaker's metal recipe file to a sophisticated data warehouse. Yet today, when we think of a database we invariably think of computerized data and their DBMSs (database management systems). How did we go from organizing our data in a simple metal filing box or cabinet to storing our data in a sophisticated computerized database? How did the computerized database evolve? This paper defines what we mean by a database. It traces the evolution of the database, from its start as a non-computerized set of related data, to the, now standard, computerized RDBMS (relational database management system). Early computerized storage methods are reviewed including both the ISAM (Indexed Sequential Access Method) and VSAM (Virtual Storage Access Method) storage methods. Early database models are explored including the network and hierarchical database models. Eventually, the relational, object-relational and object-oriented databases models are discussed. An appendix of diagrams, including hierarchical occurrence tree, network schema, ER (entity relationship) and UML (unified modeling language) diagrams, is included to support the text. This paper concludes with an exploration of current and future trends in DBMS development. It discusses the factors affecting these trends. It delves into the relationship between DBMSs and the increasingly popular object-oriented development methodologies. Finally, it speculates on the future of the DBMS.
CASTOR status and evolution
Venue: arXiv cs.OH 2003
Year: 2003

In January 1999, CERN began to develop CASTOR ("CERN Advanced STORage manager"). This Hierarchical Storage Manager targetted at HEP applications has been in full production at CERN since May 2001. It now contains more than two Petabyte of data in roughly 9 million files. In 2002, 350 Terabytes of data were stored for COMPASS at 45 MB/s and a Data Challenge was run for ALICE in preparation for the LHC startup in 2007 and sustained a data transfer to tape of 300 MB/s for one week (180 TB). The major functionality improvements were the support for files larger than 2 GB (in collaboration with IN2P3) and the development of Grid interfaces to CASTOR: GridFTP and SRM ("Storage Resource Manager"). An ongoing effort is taking place to copy the existing data from obsolete media like 9940 A to better cost effective offerings. CASTOR has also been deployed at several HEP sites with little effort. In 2003, we plan to continue working on Grid interfaces and to improve performance not only for Central Data Recording but also for Data Analysis applications where thousands of processes possibly access the same hot data. This could imply the selection of another filesystem or the use of replication (hardware or software).
Developing Open Data Models for Linguistic Field Data
Venue: arXiv cs.DL 2003
Year: 2003

The UQ Flint Archive houses the field notes and elicitation recordings made by Elwyn Flint in the 1950's and 1960's during extensive linguistic survey work across Queensland, Australia. The process of digitizing the contents of the UQ Flint Archive provides a number of interesting challenges in the context of EMELD. Firstly, all of the linguistic data is for languages which are either endangered or extinct, and as such forms a valuable ethnographic repository. Secondly, the physical format of the data is itself in danger of decline, and as such digitization is an important preservation task in the short to medium term. Thirdly, the adoption of open standards for the encoding and presentation of text and audio data for linguistic field data, whilst enabling preservation, represents a new field of research in itself where best practice has yet to be formalised. Fourthly, the provision of this linguistic data online as a new data source for future research introduces concerns of data portability and longevity. This paper will outline the origins of the data model, the content creation components, presentation forms based on the data model, data capture tools and media conversion components. It will also address some of the larger questions regarding the digitization and annotation of linguistic field work based on experience gained through work with the Flint Archive contents.
The Persint visualization program for the ATLAS experiment
Venue: arXiv cs.GR 2003
Year: 2003

The Persint program is designed for the three-dimensional representation of objects and for the interfacing and access to a variety of independent applications, in a fully interactive way. Facilities are provided for the spatial navigation and the definition of the visualization properties, in order to interactively set the viewing and viewed points, and to obtain the desired perspective. In parallel, applications may be launched through the use of dedicated interfaces, such as the interactive reconstruction and display of physics events. Recent developments have focalized on the interfacing to the XML ATLAS General Detector Description AGDD, making it a widely used tool for XML developers. The graphics capabilities of this program were exploited in the context of the ATLAS 2002 Muon Testbeam where it was used as an online event display, integrated in the online software framework and participating in the commissioning and debug of the detector system.
EU DataGRID testbed management and support at CERN
Venue: arXiv cs.DC 2003
Year: 2003

In this paper we report on the first two years of running the CERN testbed site for the EU DataGRID project. The site consists of about 120 dual-processor PCs distributed over several testbeds used for different purposes: software development, system integration, and application tests. Activities at the site included test productions of MonteCarlo data for LHC experiments, tutorials and demonstrations of GRID technologies, and support for individual users analysis. This paper focuses on node installation and configuration techniques, service management, user support in a gridified environment, and includes considerations on scalability and security issues and comparisons with "traditional" production systems, as seen from the administrator point of view.
Clarens Client and Server Applications
Venue: arXiv cs.DC 2003
Year: 2003

Several applications have been implemented with access via the Clarens web service infrastructure, including virtual organization management, JetMET physics data analysis using relational databases, and Storage Resource Broker (SRB) access. This functionality is accessible transparently from Python scripts, the Root analysis framework and from Java applications and browser applets.
BdbServer++: A User Driven Data Location and Retrieval Tool
Venue: arXiv cs.IR 2003
Year: 2003

The adoption of Grid technology has the potential to greatly aid the BaBar experiment. BdbServer was originally designed to extract copies of data from the Objectivity/DB database at SLAC and IN2P3. With data now stored in multiple locations in a variety of data formats, we are enhancing this tool. This will enable users to extract selected deep copies of event collections and ship them to the requested site using the facilities offered by the existing Grid infrastructure. By building on the work done by various groups in BaBar, and the European DataGrid, we have successfully expanded the capabilities of the BdbServer software. This should provide a framework for future work in data distribution.
HEP Applications Evaluation of the EDG Testbed and Middleware
Venue: arXiv cs.DC 2003
Year: 2003

Workpackage 8 of the European Datagrid project was formed in January 2001 with representatives from the four LHC experiments, and with experiment independent people from five of the six main EDG partners. In September 2002 WP8 was strengthened by the addition of effort from BaBar and D0. The original mandate of WP8 was, following the definition of short- and long-term requirements, to port experiment software to the EDG middleware and testbed environment. A major additional activity has been testing the basic functionality and performance of this environment. This paper reviews experiences and evaluations in the areas of job submission, data management, mass storage handling, information systems and monitoring. It also comments on the problems of remote debugging, the portability of code, and scaling problems with increasing numbers of jobs, sites and nodes. Reference is made to the pioneeering work of Atlas and CMS in integrating the use of the EDG Testbed into their data challenges. A forward look is made to essential software developments within EDG and to the necessary cooperation between EDG and LCG for the LCG prototype due in mid 2003.
A Model for Grid User Management
Venue: arXiv cs.DC 2003
Year: 2003

Registration and management of users in a large scale Grid computing environment presents new challenges that are not well addressed by existing protocols. Within a single Virtual Organization (VO), thousands of users will potentially need access to hundreds of computing sites, and the traditional model where users register for local accounts at each site will present significant scaling problems. However, computing sites must maintain control over access to the site and site policies generally require individual local accounts for every user. We present here a model that allows users to register once with a VO and yet still provides all of the computing sites the information they require with the required level of trust. We have developed tools to allow sites to automate the management of local accounts and the mappings between Grid identities and local accounts.
Exploiting peer group concept for adaptive and highly available services
Venue: arXiv cs.DC 2003
Year: 2003

This paper presents a prototype for redundant, highly available and fault tolerant peer to peer framework for data management. Peer to peer computing is gaining importance due to its flexible organization, lack of central authority, distribution of functionality to participating nodes and ability to utilize unused computational resources. Emergence of GRID computing has provided much needed infrastructure and administrative domain for peer to peer computing. The components of this framework exploit peer group concept to scope service and information search, arrange services and information in a coherent manner, provide selective redundancy and ensure availability in face of failure and high load conditions. A prototype system has been implemented using JXTA peer to peer technology and XML is used for service description and interfaces, allowing peers to communicate with services implemented in various platforms including web services and JINI services. It utilizes code mobility to achieve role interchange among services and ensure dynamic group membership. Security is ensured by using Public Key Infrastructure (PKI) to implement group level security policies for membership and service access.
GMA Instrumentation of the Athena Framework using NetLogger
Venue: arXiv cs.DC 2003
Year: 2003

Grid applications are, by their nature, wide-area distributed applications. This WAN aspect of Grid applications makes the use of conventional monitoring and instrumentation tools (such as top, gprof, LSF Monitor, etc) impractical for verification that the application is running correctly and efficiently. To be effective, monitoring data must be "end-to-end", meaning that all components between the Grid application endpoints must be monitored. Instrumented applications can generate a large amount of monitoring data, so typically the instrumentation is off by default. For jobs running on a Grid, there needs to be a general mechanism to remotely activate the instrumentation in running jobs. The NetLogger Toolkit Activation Service provides this mechanism. To demonstrate this, we have instrumented the ATLAS Athena Framework with NetLogger to generate monitoring events. We then use a GMA-based activation service to control NetLogger's trigger mechanism. The NetLogger trigger mechanism allows one to easily start, stop, or change the logging level of a running program by modifying a trigger file. We present here details of the design of the NetLogger implementation of the GMA-based activation service and the instrumentation service for Athena. We also describe how this activation service allows us to non-intrusively collect and visualize the ATLAS Athena Framework monitoring data.
The StoreGate: a Data Model for the Atlas Software Architecture
Venue: arXiv cs.SE 2003
Year: 2003

The Atlas collaboration at CERN has adopted the Gaudi software architecture which belongs to the blackboard family: data objects produced by knowledge sources (e.g. reconstruction modules) are posted to a common in-memory data base from where other modules can access them and produce new data objects. The StoreGate has been designed, based on the Atlas requirements and the experience of other HENP systems such as Babar, CDF, CLEO, D0 and LHCB, to identify in a simple and efficient fashion (collections of) data objects based on their type and/or the modules which posted them to the Transient Data Store (the blackboard). The developer also has the freedom to use her preferred key class to uniquely identify a data object according to any other criterion. Besides this core functionality, the StoreGate provides the developers with a powerful interface to handle in a coherent fashion persistable references, object lifetimes, memory management and access control policy for the data objects in the Store. It also provides a Handle/Proxy mechanism to define and hide the cache fault mechanism: upon request, a missing Data Object can be transparently created and added to the Transient Store presumably retrieving it from a persistent data-base, or even reconstructing it on demand.
The MammoGrid Project Grids Architecture
Venue: arXiv cs.DC 2003
Year: 2003

The aim of the recently EU-funded MammoGrid project is, in the light of emerging Grid technology, to develop a European-wide database of mammograms that will be used to develop a set of important healthcare applications and investigate the potential of this Grid to support effective co-working between healthcare professionals throughout the EU. The MammoGrid consortium intends to use a Grid model to enable distributed computing that spans national borders. This Grid infrastructure will be used for deploying novel algorithms as software directly developed or enhanced within the project. Using the MammoGrid clinicians will be able to harness the use of massive amounts of medical image data to perform epidemiological studies, advanced image processing, radiographic education and ultimately, tele-diagnosis over communities of medical "virtual organisations". This is achieved through the use of Grid-compliant services [1] for managing (versions of) massively distributed files of mammograms, for handling the distributed execution of mammograms analysis software, for the development of Grid-aware algorithms and for the sharing of resources between multiple collaborating medical centres. All this is delivered via a novel software and hardware information infrastructure that, in addition guarantees the integrity and security of the medical data. The MammoGrid implementation is based on AliEn, a Grid framework developed by the ALICE Collaboration. AliEn provides a virtual file catalogue that allows transparent access to distributed data-sets and provides top to bottom implementation of a lightweight Grid applicable to cases when handling of a large number of files is required. This paper details the architecture that will be implemented by the MammoGrid project.
Prototyping Virtual Data Technologies in ATLAS Data Challenge 1 Production
Venue: arXiv cs.DC 2003
Year: 2003

For efficiency of the large production tasks distributed worldwide, it is essential to provide shared production management tools comprised of integratable and interoperable services. To enhance the ATLAS DC1 production toolkit, we introduced and tested a Virtual Data services component. For each major data transformation step identified in the ATLAS data processing pipeline (event generation, detector simulation, background pile-up and digitization, etc) the Virtual Data Cookbook (VDC) catalogue encapsulates the specific data transformation knowledge and the validated parameters settings that must be provided before the data transformation invocation. To provide for local-remote transparency during DC1 production, the VDC database server delivered in a controlled way both the validated production parameters and the templated production recipes for thousands of the event generation and detector simulation jobs around the world, simplifying the production management solutions.
How many candidates are needed to make elections hard to manipulate?
Venue: arXiv cs.GT 2003
Year: 2003

In multiagent settings where the agents have different preferences, preference aggregation is a central issue. Voting is a general method for preference aggregation, but seminal results have shown that all general voting protocols are manipulable. One could try to avoid manipulation by using voting protocols where determining a beneficial manipulation is hard computationally. The complexity of manipulating realistic elections where the number of candidates is a small constant was recently studied (Conitzer 2002), but the emphasis was on the question of whether or not a protocol becomes hard to manipulate for some constant number of candidates. That work, in many cases, left open the question: How many candidates are needed to make elections hard to manipulate? This is a crucial question when comparing the relative manipulability of different voting protocols. In this paper we answer that question for the voting protocols of the earlier study: plurality, Borda, STV, Copeland, maximin, regular cup, and randomized cup. We also answer that question for two voting protocols for which no results on the complexity of manipulation have been derived before: veto and plurality with runoff. It turns out that the voting protocols under study become hard to manipulate at 3 candidates, 4 candidates, 7 candidates, or never.
Defying Dimensions Mod 6
Venue: arXiv cs.CC 2003
Year: 2003

We show that a certain representation of the matrix-product can be computed with $n^{o(1)}$ multiplications. We also show, that siumilar representations of matrices can be compressed enormously.
Deterministic Sampling and Range Counting in Geometric Data Streams
Venue: arXiv cs.CG 2003
Year: 2003

We present memory-efficient deterministic algorithms for constructing epsilon-nets and epsilon-approximations of streams of geometric data. Unlike probabilistic approaches, these deterministic samples provide guaranteed bounds on their approximation factors. We show how our deterministic samples can be used to answer approximate online iceberg geometric queries on data streams. We use these techniques to approximate several robust statistics of geometric data streams, including Tukey depth, simplicial depth, regression depth, the Thiel-Sen estimator, and the least median of squares. Our algorithms use only a polylogarithmic amount of memory, provided the desired approximation factors are inverse-polylogarithmic. We also include a lower bound for non-iceberg geometric queries.